In recent years, hermeticity and high thermal insulation of rooms have been developed for energy saving. Therefore, natural ventilation of rooms cannot be expected so much, and importance of a heat exchange ventilator capable of simultaneously realizing ventilation and air conditioning, particularly a total-heat type heat exchange ventilator having high heat exchanging efficiency is increased. The total-heat type heat exchange ventilator includes a total-heat type heat exchanger that performs both an exchanging operation of sensible heat and an exchanging operation of latent heat. The heat exchanger includes a total-heat type heat exchange element that performs both an exchanging operation of sensible heat and an exchanging operation of latent heat, and a frame body in which the heat exchange element is accommodated.
The total-heat type heat exchange element has a structure such that sheet-like partition members and corrugated spacing members are alternately joined one another. A moisture absorbent is added at least to the partition member. A plurality of air flow passages are formed by the partition member and the spacing member located under the partition member. A plurality of air flow passages are formed by the partition member and the spacing member located on the partition member. The exchanging operation of sensible heat and the exchanging operation of latent heat are performed between an air current flowing through the flow passages formed under the partition member and an air current flowing through the flow passages formed on the partition member through the partition members. A primary air current generated by supply of air from outside into a room is supplied to one of a flow passage formed under the partition member and a flow passage formed on the partition member, and a secondary air current generated by discharging air from the room to outside is supplied to the other flow passage.
The total-heat type heat exchange element is accommodated is in the frame body. The frame body is a box that is provided at its four sides with rectangular openings. The total-heat type heat exchange element is accommodated in the frame body such that an upper surface or a lower surface of each member in the layer stacking direction is oriented downward. The primary air current whose heat is to be exchanged flows into the heat exchanger through a predetermined rectangular opening formed in the frame body, and after the primary air current flows through the total-heat type heat exchange element, the primary air current flows out from the heat exchanger through a rectangular opening that is opposed to the rectangular opening described above. Similarly, the secondary air current whose heat is to be exchanged flows into the heat exchanger through another rectangular opening formed in the frame body, and after the secondary air current flows through the total-heat type heat exchange element, the secondary air current flows out from the heat exchanger through a rectangular opening that is opposed to the opening described above.
In the total-heat type heat exchange element, the exchanging operation of sensible heat and the exchanging operation of latent heat are performed through the partition members. Therefore, the heat exchanging efficiency in the heat exchange element is largely dependent on an effective moisture permeation area and heat conductivity of the partition member. Reduction in the effective moisture permeation area and reduction in the heat conductivity can be a factor that deteriorates the heat exchanging efficiency of the total-heat type heat exchange element. For example, when an adhesive of low moisture permeability is used and the partition member and the spacing member are joined to each other, the effective moisture permeation area of each partition member is reduced and the exchanging efficiency of latent heat is lowered.
To suppress the reduction in the effective moisture permeation area caused by an adhesive, according to a heat exchanger described in Patent Document 1, a partitioning plate (partition member) and a spacing member plate (spacing member) are joined to each other through a fluorine-based resin or a hydrocarbon-based resin of high hygroscopicity and moisture diffusibility. Further, according to a filter unit for a heat exchanger described in Patent Document 2, in laminating a large number of filters in which a flat liner (partition member) and a corrugated plate (spacing member) are joined to each other through an adhesive, only peripheries of filters that are adjacent to each other in the vertical direction (layer stacking direction) are joined to each other through an adhesive.
Meanwhile, to enhance the heat conductivity of the heat exchange element, according to a cooling absorption element described in Patent Document 3, a plurality of holes are formed in an entire corrugated plate (spacing member), flow passages formed by a flat plate (partition member) and a corrugated plate located on or under the flat plate are brought into communication with each other through the holes, thereby disturbing a flow of air and, with this structure, the heat conductivity is enhanced. Similarly to this cooling absorption element, also according to a plate-fin type heat exchanger described in Patent Document 4, a plurality of holes are formed in an entire fin (spacing member), flow passages formed by a plate (partition member) and a fin located on or under the plate are brought into communication with each other through the holes, thereby disturbing a flow of air and with this arrangement, the heat conductivity is enhanced.
If the plurality of holes are formed in the spacing member as described above, the heat conductivity is enhanced and the weight of the heat exchange element is reduced. In the case of a heat exchange ventilator of a type having a main body arranged under a roof, or a heat exchange ventilator of a type that is suspended from a ceiling, it is very preferable that the weight of the heat exchange ventilator is reduced to prevent the ventilator from falling at the time of an earthquake or the like and to enhance safety. Further, when a plurality of holes are formed in the spacing member, an adhesive is not applied to a portion of the spacing member where the hole is formed. Therefore, even when a partition member and a spacing member are joined to each other using an adhesive having poor hygroscopicity, poor moisture diffusibility and poor moisture permeability, an effective moisture permeation area of the heat exchange element can be easily widened. As a result, it becomes easy to obtain a heat exchange element having high exchanging efficiency of latent heat.
Patent Document 1: Japanese Patent Application Laid-open No. 2005-24207
Patent Document 2: Japanese Patent Application Laid-open No. 2005-201502
Patent Document 3: Japanese Patent Application Laid-open No. 2003-144834
Patent Document 4: Japanese Utility Model Application Laid-open No. S55-145290